The present invention relates to a method of inspecting a limited slip differential (or differential limiting-device) which functions to limit or restrict a differential movement between the right wheel and the left wheel of a vehicle or a differential movement between the front wheels and the rear wheels of a four-wheel drive vehicle.
As can be seen in Japanese Published Unexamined Utility Model Registration Application No. 84544/1988, there is known a method of inspecting a limited slip differential in which: one wheel and the other wheel of a vehicle, differential movement therebetween being limited, are respectively mounted on rolls; accelerating operation of the vehicle, i.e., depressing of an accelerator pedal is performed under a condition in which a flywheel is connected to that one of the rolls on which said one wheel is mounted, said flywheel restraining the rotation of said one roll; a difference in rotational speed between said one roll and said the other roll on which said the other wheel is mounted is measured at the time of this accelerating operation; and the limited slip differential is judged to be unacceptable if the measured difference in rotational speed is above a predetermined value.
In the above-described method, it is possible to judge only as to whether the limited slip differential has operated or not, and there cannot be obtained a judgement on the acceptability or unacceptability of the operating conditions of the limited slip differential, i.e., a judgement as to whether it has operated according to its predetermined operating characteristics or not. In addition, since the difference in rotational speed between both rolls varies with the degree of acceleration, there are possibilities that the following may occur. Namely, at the time of sudden acceleration, even if the limited slip differential is normal, the difference in rotational speed between both rolls may exceed a predetermined value or, on the other hand, at the time of gradual or gentle acceleration, even if the limited slip differential is abnormal, the difference in rotational speed may lie below a predetermined value. There is, therefore, a disadvantage in that this kind of occurrence results in lack of reliability of inspection.
In view of the above-described disadvantages, the present invention has an object of providing a method in which the operating conditions of the limited slip differential can be accurately judged regardless of the degree of acceleration.